Foundations for Houses in Chile: Depth and Types of Foundations

It Starts with the Feet: Foundations

It is the part of the house that no one sees, but it is the only one that cannot be easily fixed if it fails. At Canadian Houses, we take foundations with scientific seriousness.

The question "how deep should the foundation be?" does not have a single answer, because it depends 100% on what is under your feet.

Soil Types in Chile and their Solution

1. "Good" Soil (Gravel, Compact Fill):

   • These are firm and stable soils.
   • Solution: Foundation slab or traditional strip footing at 60-80 cm depth is sufficient to find the "foundation seal."

2. Clay Soil (Common in Chicureo, Colina, Rancagua):

   • Clay is treacherous. It swells when it rains (pushing the house up) and contracts when it dries (leaving the house in the air).
   • Solution: Requires "soil improvement" (removing clay and putting stabilized fill) or deeper, reinforced foundations that prevent the house from splitting.

3. Sandy Soil (Coast):

   • Sand liquefies with earthquakes (liquefaction) or shifts.
   • Solution: Raft-type foundations (losa colaborante) that act as a "raft" floating on the sand without breaking apart.

Our Quality Standard

• Plant Concrete: We do not mix cement with a shovel on-site (unless inaccessible). We use mixer trucks with certified H25 or H30 concrete.
• Ribbed Steel: All our foundations carry reinforcement. Concrete only resists compression; iron gives it the necessary tensile strength for earthquakes.
• Waterproofing: We apply barriers (membrane, polyethylene sleeves) between the ground and the concrete to cut rising damp.

Technical Note: In two-story houses, load is higher. Here the engineer's calculation is law. Never accept a builder who does foundations "by eye."